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PubMed2006

Quantitative assessment of myocardial perfusion defects with real-time three-dimensional myocardial contrast echocardiography.

OBJECTIVE: To evaluate the feasibility and accuracy of measurement of myocardial perfusion defects with intravenous contrast-enhanced real-time three-dimensional echocardiography (CE-RT3DE). METHODS: RT3DE was performed in 21 open-chest mongrel dogs undergoing acute ligation of the left anterior descending artery (LAD, n = 14) or distal branch of the left circumflex artery (LCX, n = 7). A perfluorocarbon microbubble contrast agent was injected intravenously to assess the resulting myocardial perfusion defects with Philips Sonos-7500 ultrasound system. Evans blue dye was injected into the occluded coronary artery for subsequent anatomic identification of underperfused myocardium. In vitro anatomic measurement of myocardial mass after removal of the animal's heart was regarded as the control. Blinded off-line calculation of left ventricular mass and perfusion defect mass from RT3DE images were performed using an interactive aided-manual tracing technique. RESULTS: Total left ventricular (LV) myocardial mass ranged from 38.9 to 78.5 (mean +/- SD: 60.0 +/- 10.1) g. The mass of perfusion defect ranged from 0 to 21.4 (mean +/- SD: 12.0 +/- 5.0) g or 0 to 27% of total LV mass (mean +/- SD: 19% +/- 6%). The RT3DE estimation of total LV mass (mean +/- SD: 59.8 +/- 9.9 g) strongly correlated with the anatomic measurement (r = 0.98; y = 2.01 + 0.96x). The CE-RT3DE calculation of the mass of underperfused myocardium (mean +/- SD: 12. 3 +/- 5.3 g) also strongly correlated with the anatomic measurement (r = 0. 96; y = - 0.10 + 1.04x) and when expressed as percentage of total LV mass (r = 0.95; y = -0.20 + 1.04x). CONCLUSIONS: RT3DE with myocardial contrast opacification could accurately estimate underperfused myocardial mass in dogs of acute coronary occlusion and would play an important role in quantitative assessment of myocardial perfusion defects in patients with coronary artery disease.

Animals↗

PubMed2006

Australian and New Zealand perfusion survey: equipment and monitoring.

The current practice of perfusion in Australia and New Zealand continues to adopt new techniques and procedures into clinical practice. Our aims were to report current practice in 2003 and to compare and contrast current practice with historic practice. A total of 62 centers (40 perfusion groups) performing procedures using cardiopulmonary bypass (CPB) were identified and were e-mailed a detailed electronic survey. The survey was comprised of an excel worksheet that contained 233 single answer questions (either dropdown lists, yes/no, true/false, or numeric) and 12 questions that allowed the respondent to provide a commentary. Respondents were instructed to answer all questions based on what represented the predominant practice of perfusion in their institutions during 2003. We report an 89% response rate representing a caseload of 20,688 adult cases. These data allowed us to profile the following. A standard adult CPB setup in 2003 consisted of a membrane oxygenator (100% of cases), a roller pump (70%) as the main arterial pump, although a centrifugal pump would be considered for selected procedures (30%), a circuit incorporating a hard-shell venous reservoir (86%), and a mixture of biocompatible and non-biocompatible circuit components (66%). The circuit would include a pre-bypass filter (88%), an arterial line filter (94%), and would allow monitoring of the following: hard-shell venous reservoir low level (100%) with servo-regulation of the arterial pump (85%), microbubble alarm (94%) with servo-regulation of the arterial pump (79.5%), arterial line pressures (100%) with servo-regulation of the arterial pump (79%), inline venous O2 saturation (100%), and inline hematocrit (58%). Perfusion practice in Australia and New Zealand has adopted changes over the last decade; however, some areas of practice show wide variation. This survey provides a baseline of contemporary practice for Australian and New Zealand perfusionists.

Adult↗

PubMed2006

[Patent foramen ovale, stroke, and echocardiography: diagnostic methodology and appropriateness of indications].

A patent foramen ovale is a frequent remnant of embryological development with clinical importance in stroke, decompression sickness, and migraine headache. The proposed mechanisms of stroke include paradoxical embolization, in situ thrombosis within the canal of the foramen, associated atrial arrhythmias. Cardiac right-to-left shunts can be identified by echocardiography and by transcranial Doppler ultrasound with the use of contrast agents and a Valsalva maneuver as provocation procedure. Relative value of different diagnostic tests, appropriate timing of the Valsalva maneuver, use of a diagnostic time window, and threshold in contrast agent microbubbles detection are thoroughly discussed. The value of echocardiography or of other diagnostic tests does not elucidate the effect of test results on patient management. The appropriate use of imaging requires an understanding of both the capabilities of the imaging technique and the value of therapy used to treat the identified condition. New information that does not improve outcome has no value. In patients with a cryptogenic stroke and an atrial septal abnormality the evidence is insufficient to determine whether warfarin or aspirin is superior in preventing recurrent stroke or death, but minor bleeding is more frequent with warfarin. There is insufficient evidence to evaluate the efficacy of surgical or endovascular closure.

Echocardiography, Transesophageal↗

PubMedDate not supplied

[A contrast with good intentions].

A seventy-five-year-old woman with moderate chronic renal failure was admitted to evaluate a complex renal cyst in the frame of acquired cystic kidney disease. Computed tomography (CT) was performed without contrast media due to the risk of radiocontrast-induced nephrotoxicity. Sonographic investigation at our ultrasound unit revealed a hypoechoic lesion measuring 20x20 mm in size by conventional B-mode sonography, confirmed by NTHI. The Hypoechoic lesion was consistent with complex renal cyst or renal tumour. This finding triggered investigation with CEUS.A sulphur hexafluoride-filled microbubble contrast medium was injected intravenously. The focal lesion CES pattern was characterized by intralesional enhancement in the arterial phase. Further diagnostic imaging including CT with contrast media confirmed a lesion consistent with renal tumour. The patient underwent right-sided nephrectomy; histopathological work-up revealed a renal cell carcinoma. Contrast-enhanced sonography could be clinically useful for the differential diagnosis of kidney lesions in patients with chronic renal failure.

Aged↗

PubMed1991

[Myocardial contrast echocardiography with sonicated iopromide (Ultravist 370) before and after coronary angioplasty].

Thirty-one patients (3 female, 28 male, mean age 56 years) were investigated with myocardial contrast echocardiography before and after successful PTCA (= less than 30% residual stenosis) of one major coronary artery. 2 ml of sonicated lopromid (Ultravist 370, microbubble-size 6 +/- 4 microns) were injected into the coronary vessel. Before, during and after injection a short-axis view or an apical four chamber view was obtained and recorded on videotape. Computer-assisted videodensitometry was performed in a region of interest placed between endo- and epicardium of the myocardial area supplied by the dilated vessel to analyze contrast decay half-time (t/2), time from onset of opacification to t/2 (T-t/2) and maximal videointensity (Imax). 27 patients (87%) had adequate echorecordings before and after PTCA, no side-effects occurred. Contrast decay half-time and T-t/2 showed a decrease in 21/27 (78%) patients (8.7 +/- 6.1 vs 5.8 +/- 3.7s, p less than 0.001) and in 19/27 (70%) patients (12.0 +/- 8.4 vs 8.7 +/- 5.0 s, p less than 0.002) respectively. Imax was not significantly altered by the intervention. Most of the patients without decrease of t/2 and T-t/2 either had moderate coronary stenosis or a preexisting myocardial infarction in the region supplied by the dilated vessel. Thus contrast echocardiography seems to be suitable to assess alterations in myocardial blood flow during PTCA by determination of contrast decay half-time and T-t/2.

Angina Pectoris↗

PubMed1991

The use of two-dimensional echocardiography during catheter ablation of the atrioventricular node.

Atrioventricular nodal catheter ablation has proved an effective option in patients with drug-refractory, uncontrolled, supraventricular tachyarrhythmias; however, many complications in the immediate post ablative period relate to direct myocardial damage due to the electrical current generated by the catheter. The authors used two-dimensional echocardiography in a 57-year-old female patient with recurrent uncontrolled rapid ventricular rates despite multiple antiarrhythmic medications, in an attempt to identify the sequence of events responsible for complications of the ablation procedure. The echocardiographic images showed evidence of an explosion: microbubbles outlining an expanding force were seen which, if contained in a confined space such as the coronary sinus, might explain previously observed mechanical damage. Two-dimensional echocardiography may be useful for continual monitoring of catheter position during ablation.

Arrhythmias, Cardiac↗

PubMed1991

Ultrasound contrast agents.

Two concepts of microbubble stabilization led to reproducible, industrially manufactured contrast agents, and to the transpulmonary stability of agents after intravenous injection. The albumin microencapsulation concept is represented by Albunex (Molecular Biosystems, San Diego, CA), the saccharide microparticle concept is represented by SH U 454 (Echovist and its transpulmonary derivative SH U 508 A, Schering AG, Berlin, FRG). In the past year, the first reported clinical studies of the transpulmonary agents have demonstrated their safety and efficacy. Further, the results of contrast-enhanced pulsed wave and color Doppler studies bring prospects of further improvements in vascular Doppler examinations. The patency of fallopian tubes was assessed with transvaginal scanning and transcervical injection of echogenic contrast agents. The feasibility of sonographic perfusion imaging of different organs (eg, myocardium, liver, tumors) was demonstrated using invasive injection techniques. Thus, ultrasound contrast agents are a new diagnostic tool in sonography and have a broad spectrum of potential indications.

Animals↗

PubMed1990

[Color Doppler echocardiography].

Colour-coded doppler echocardiography uses a pulsed doppler shooting lines scanning system to perform a true real-time doppler angiography of intracradiac flows. Combined with ultrasonic imaging, it has proved irreplaceable for the diagnosis of leakages and for direct visualization of intracradiac shunts; by determining the anatomical location of the jet it facilitates an accurate pulsed and continuous Doppler study. Aortic leakages are best evaluated by measuring the jet at its point of origin. The quantification of moderate to medium leakages remains difficult since it depends on numerous factors and needs integration of other echocardiographic data. Echocardiographic contrast tests after intravenous injection of microbubbles diagnose the right-to-left shunts by the passage of contrast into the left cavities, and the left-to-right shunts by a washing image.

Echocardiography, Doppler↗

PubMed1990

Diagnostic contrast echocardiography in children with congenital heart disease.

905 diagnostic contrast echocardiographic studies (DCE) were performed on 223 children. Carbon dioxide microbubble was used as contrast agent in various age groups, especially in newborns and infants because of its safety in application, stable contrast effect, and peripheral vein injection. Two-dimensional echocardiography (2-DCE), a useful tool in diagnosis of left to right shunt lesions reduced false negative diagnoses for ventricular septal defects and eliminated false positive diagnosis for atrial septal defects and patent ductus arteriosus. The accuracy of diagnosis in this series was 97%. The results of this series showed that 2-DCE is also valuable in the diagnosis of congenital heart disease with right to left shunts, and can be used to evaluate shunt levels and determine the obstructive sites on the right side of the heart.

Adolescent↗

PubMed1990

Contrast echocardiography: a method to visualize changes in regional myocardial perfusion in the dog model for CABG surgery.

The ability of contrast echocardiography to assess regional myocardial perfusion during cardiopulmonary bypass in a dog model for coronary artery bypass surgery was evaluated. Sonicated Renograffin-76 microbubbles (meglumin diatrigoate and sodium diatrigoate) were injected into an aortic root proximal to an aortic occlusion clamp root while dogs were on cardiopulmonary bypass, with the heart arrested in diastole. Echocardiographic contrast-enhanced regions of myocardial perfusion were easily visualized. Differences in contrast-enhanced myocardial regions depended on coronary artery occlusion or patency. The contrast-enhanced images of myocardial perfusion showed that, for a given myocardial segment of the supplying vessel, the presence or absence of contrast effect reliably predicted vessel occlusion or patency (P less than .01). In the future contrast echocardiography may allow the direct assessment of regional myocardial perfusion in the operating room.

Animals↗

PubMed1990

Intraoperative perfusion contrast echocardiography. Initial experience during coronary artery bypass grafting.

Intraoperative evaluation of the effectiveness of myocardial revascularization has been limited by an inability to assess regional myocardial perfusion. Microbubbles of sonicated diatrizoate sodium and diatrizoate meglumine (Renografin) have been an effective echocardiographic contrast agent and have been employed clinically during cardiac catheterization. This recent development in contrast-enhanced two-dimensional echocardiography permits real-time imaging of transmural myocardial blood flow but has not been evaluated in the operating room. This study represents the initial surgical application of this directed technique and was designed to evaluate the safety and efficacy of intraoperative perfusion contrast echocardiography in assessing the results of coronary artery bypass grafting. Twenty men with significant coronary artery disease ranging in age from 49 to 73 years were studied. Direct contrast agent injection into completed saphenous vein bypass grafts caused the myocardium supplied by each graft to be well delineated and provided a tomographic view of contrast distribution. The enhanced region was well correlated with the size and distribution of the native vessel. Rapid contrast washout (less than 20 seconds) indicated satisfactory regional perfusion. Contrast echocardiography prolonged the operation less than 10 minutes and did not result in any perioperative complications.

Aged↗

PubMed1989

[Improvement of extracorporeal circulation on the basis of anaphylatoxin levels, with special reference to oxygenation mechanisms and plasma denaturation by oxygen bubbling].

Complement activation was evaluated in 76 patients undergoing cardiopulmonary bypass (CPB) with particular reference to anaphylatoxin levels. These patients were divided into membrane (MOG) and bubble oxygenator groups (BOG). The influence of primed homologous to circulating autologous blood volume (H/A) ratio was also examined. Each group was further divided into two subgroups: one was primed with homologous whole blood, and the other with fresh homologous concentrated red cells (CRC) and human albumin. C4a slowly increased during CPB in both groups, maintaining slightly higher levels in the BOG than in the MOG. A marked initial rise was observed in the BOG with high H/A ratios. C3a increased more steeply in the BOG than in the MOG. C5a levels in the BOG were higher than in the MOG. The influence of the H/A ratio was milder in the MOG than in the BOG. In the BOG, the anaphylatoxin levels in the group primed with CRC and human albumin were slightly lower than in the group primed with whole blood. However, anaphylatoxin levels rose most steeply in cyanotic patients even though they were perfused with a membrane oxygenator. In experimental studies using 20 monkeys (Macaca fascicularis), continuous intraaortic infusion with O2 bubbled autologous blood increased C4a and C3a levels, while autologous blood extracorporeally contacted with nylon increased C3a levels alone. C4a and C3a levels were unchanged by infusion with O2 microbubbles. In vitro studies revealed that human immunoglobulin denatured by O2 bubbling produced C4a, C3a, and C5a in a dose dependent manner, although human albumin treated identically as human immunoglobulin did not produce them.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

[A study on complement activation in cardiopulmonary bypass--experimental and clinical evaluations].

Complement activation in patients undergoing cardiopulmonary bypass (CPB) was studied, with particular reference to anaphylatoxins. Complement levels were compared between a bubble oxygenator group (BOG) and a membrane oxygenator group (MOG). The influence of primed homologous blood on complement activation was also evaluated. C4a levels gradually increased during CPB in the BOG, whereas in the MOG they changed little. There was a marked initial rise of C4a levels in the BOG of high H/A (primed homologous vs. circulating autologous blood volume ratio). C3a levels increased more steeply in the BOG than in the MOG. In general C5a levels remained low in both groups, but were slightly higher in the BOG than in the MOG. Complement levels were determined in monkeys (Macaca fascicularis) undergoing continuous intraaortic infusion of 1) autologous blood extracorporeally bubbled with O2, 2) blood contacted with nylon, or 3) O2 microbubbles. The results indicated 1) elevation of C4a and C3a in the bubbled blood group, 2) elevation of C3a alone in the nylon group, and 3) no elevation of either anaphylatoxin. It was thus inferred that 1) during CPB, the complement might be rather dominantly activated via the classical pathway in the BOG, and via the alternative pathway in the MOG, 2) higher anaphylatoxin levels in the BOG than in the MOG might be related to mode and grade of blood trauma including plasma denaturation, and 3) the H/A ratio might be a factor able to modify complement activation.

Adolescent↗

PubMed1986

[Diagnosis of atrial septal defects by contrast echocardiography with sensitivity increased by coughing].

The aim of this study was to assess the sensitivity of contrast echocardiography in the diagnosis of permanent (atrial septal defects, ASD) and transient (patent foramen ovale, PFO) interatrial communications under basal conditions, after Valsalva manoeuvres and coughing. Sixty-four patients suspected of having defects of the interatrial septum were studied. The results of echocardiography were compared with those of cardiac catheterisation, the classical method of reference. The sensitivity of contrast echocardiography was significantly improved in the diagnosis of PFO by the cough test (100%) compared with contrast echocardiography during spontaneous respiration (55%). Similarly, the cough test increased the sensitivity of contrast echocardiography in the diagnosis of ASD (96% compared to 83%). The specificity was good in both cases, about 90%. The cough test was a better method (98%) than Valsalva manoeuvres (59%) for the potentiation of interatrial right-to-left shunts. The results of echocardiography and catheterisation explain the mechanism of the right-to-left shunt during spontaneous respiration, Valsalva manoeuvres and coughing. The passage of the microbubbles from the right to the left atrium occurs during early systole when the atrioventricular valves are closed. The right-to-left shunt is potentiated by provocative manoeuvres. The demonstration of a right-to-left shunt by contrast echocardiography therefore indicates the presence of an interatrial communication; our results show that this non-invasive technique is a reliable method of diagnosing ASD and PFO.

Adolescent↗

PubMed1986

Cerebral vasoreactivity and arterial gas embolism.

Compression regimens effect redistribution of entrapped cerebral arterial gas emboli by reducing embolus length and/or by increasing local perfusion pressure. Embolus length is related to embolus volume and vessel diameter. It has been assumed without evidence that cerebral arterial gas emboli induce local vasoparalysis and hence that the relevant vessel diameter will not be affected by the treatment regimen. This study tested that assumption. Infusion of gas microbubbles into the femoral artery of upright rabbits caused significant but transient hypertension, respiratory depression, cardiac bradyarrythmia, inhibition of cerebrovascular autoregulation to blood pressure changes, and cerebral arterial gas embolism, with entrapment of long emboli in arterioles of 50-200 micron diameter. Cerebral arterioles constricted and dilated appropriately with sequential changes in ventilation gas mixture both before and after gas embolism. The study demonstrated that cerebral arterial gas emboli did not necessarily inhibit cerebrovascular reactivity and that the effect a compression regimen has on cerebral arteriole diameter should be included in any assessment of its efficacy.

Administration, Inhalation↗

PubMed1988

[Improving color Doppler echocardiography of the right heart chambers following intravenous injection of SHU 454].

The echocardiographic contrast agent SHU 454 provides microbubbles of defined size (median 3 micron) in a solution of galactose and is available in different reproducible concentrations. In 22 patients with suspected tricuspid regurgitation, color flow mapping (CFM) Doppler echocardiography was performed before and after intravenous injection of 2-4 ml SHU 454. Without SHU 454 the diastolic blood flow was imaged on 13.6 +/- 7.5% (mean value + standard deviation) of the cross sectional area of the right ventricle (four-chamber view) in comparison to 39.0 +/- 15.0% with SHU 454 (p less than 0.001). For the right atrium, the area analyzed by CFM increased from 9.4 +/- 12.9% to 62.4 +/- 25.3% (p less than 0.001). The interindividual variability of measurements after injection of SHU 454 was 5.9 +/- 4.0% as compared to 10.7 +/- 6.9% without SHU 454 (p less than 0.05). These findings demonstrate that intravenous SHU 454 administration increases the detection of blood flow by CFM within the right heart.

Adult↗

PubMedDate not supplied

[Therapeutic possibilities of venolymphatic disorders using thalassotherapy].

Venolymphatic pathology of the lower extremities represents a major part of the recruiting of a specialized thalassotherapy center, such as "Les Cures Marines de Trouville". The various treatments are adjusted according to each clinical case. The main techniques which are prescribed, include alternatively: active rehabilitation in sea-water pool at 34 degrees C; underwater showers and manual massages of the connective tissue; shower sprays; microbubbles; algi baths. The temperature of the baths and showers ranges between 32 and 35 degrees C. An example of the treatments administered in Trouville consists in underwater lymphatic drainage, performed by the physical therapist in a large tank, at minimum pressure. It begins with a symmetrical drainage of the trunk (or basic protocol), then drainage of the lymphedema, always starting at the root of the limb. Hygiene-dietetic rules are discussed in detail during the consultation. A fitted elastic bandage is prescribed at the end of the treatment.

Balneology↗

PubMed1987

Quantitative assessment of myocardial blood flow by contrast two-dimensional echocardiography: initial clinical observations.

Myocardial contrast two-dimensional echocardiography (MC-2DE) is a new technique to study myocardial perfusion imaging. Whether quantitative analysis of MC-2DE has any clinical significance is not known. We studied 12 patients during cardiac catheterization and coronary arteriography by MC-2DE, using sonicated iopamidol (microbubble size 12 +/- 4 micron) as the echocontrast agent. Selective intracoronary injections of 4 cc were performed into the left and right coronary artery. Two-dimensional echocardiograms were made before, during, and after injection from the apical four-chamber view. The coronary artery stenosis was calculated by automated boundary detection from the digitized cine arteriograms and expressed as percentage area stenosis (%S); also the absolute minimal luminal area (L) was calculated. From the MC-2DE video images, end-diastolic frames were chosen for digitization and videointensity measured from a region of interest at basal or midseptal level. This analysis reveals a curve of echo intensity versus time. From these curves, total curve area (A), curve duration (T), and time from peak intensity to 50% intensity decay (T50) were measured. Multiple regression analysis reveals the best correlation between %S and A (A = 52.48. e0.02%S; P less than .0001; r = 0.89). Correlations between %S, L, and T and T50, respectively, were less. Thus MC-2DE quantitative analysis shows a good agreement with anatomical size of coronary artery stenosis. These findings might have important clinical implications for future follow-up of various therapeutic procedures such as transluminal angioplasty thrombolysis.

Adult↗